Important Reservoir Research Articles

Solid-liquid redistribution and degradation of antibiotics during hydrothermal treatment of sewage sludge: Interaction between biopolymers and antibiotics

Waste activated sludge serves an important reservoir for antibiotics within wastewater treatment plants, and understanding the occurrence and evolution of antibiotics during sludge treatment is crucial to mitigate the potential risks of subsequent resource utilization of sludge. This study explores the degradation and transformation mechanisms of three typical antibiotics, oxytetracycline (OTC), ofloxacin (OFL), and azithromycin (AZI) during sludge hydrothermal treatment (HT), and investigates the influence of biopolymers transformation on the fate of these antibiotics. The findings indicate that HT induces a shift of antibiotics from solid-phase adsorption to liquid-phase dissolution in the initial temperature range of 25–90 °C, underscoring this phase's critical role in preparing antibiotics for subsequent degradation phases. Proteins (PN) and humic acids emerge as crucial for antibiotic binding, facilitating their redistribution within sludge. Specifically, the binding capacity sequence of biopolymers to antibiotics is as follows: OFL>OTC>AZI, highlighting that OFL-biopolymers display stronger electrostatic attraction, more available adsorption sites, and more stable binding strength. Furthermore, antibiotic degradation mainly occurs above 90 °C, with AZI being the most temperature-sensitive, degrading 92.97% at 180 °C, followed by OTC (91.26%) and OFL (52.51%). Concurrently, the degradation products of biopolymers compete for active sites to form novel amino acid-antibiotic conjugates, which inhibits the further degradation of antibiotics. These findings illuminate the effects of biopolymers evolution on intricate dynamics of antibiotics fate in sludge HT and are helpful to optimize the sludge HT process for effective antibiotics abatement.

Rat lungworm, Cryptosporidium and other zoonotic pathogens of Rattus rattus and native wildlife on Sydney's Northern beaches

ABSTRACT Urbanisation is disrupting natural habitats and potentially causing spillover of zoonotic diseases from animals common in highly populated areas to natural environments and native wildlife. The black rat (Rattus rattus) is a common commensal species abundant in urban areas and nearby bushland in Australia and globally. It can be a major reservoir of pathogens and vectors for diseases that affect humans, pets, and wildlife. We examined pathogen prevalence in black rats and native wildlife in peri-urban northern Sydney. We trapped rats and native wildlife at eight 1-ha bushland sites and sampled for a range of internal pathogens from necropsied individuals (n=85 rats) and animal/trap swabs (n=54 native individuals). We detected a high prevalence of rat lungworm (Angiostrongylus spp.) in black rats (67%) as well as native wildlife including long-nosed bandicoots (Perameles nasuta; 43%; previously undetected) and bush rats (R. fuscipes; 33%). Incidence of detection tended to be more frequent where rat activity was greatest. Non-zoonotic Cryptosporidium spp. was also recorded in 17% of black rats and Salmonella spp. in 21% of bandicoots. Our findings suggest black rats may be facilitating spill-over of disease into native wildlife. The detected prevalence of Angiostrongylus spp. suggests an increasing occurrence in this natural system. These data provide valuable insight for disease management highlighting important reservoirs of disease which could be targeted to reduce disease burden in humans, pets, and wildlife.

Preliminary Assessment of Alfalfa Crop Trap Strategy in Regulating Natural Predators for Aphis gossypii Glover Control

Aphis gossypii Glover is an important pest in cotton plantations. Medicago sativa L. (alfalfa) is a host plant for the aphid Aphis craccivora Koch and may prove to be an important reservoir of natural enemies to combat this pest. The objective of this study was to analyze the impact of different mowing frequencies of alfalfa traps on A. gossypii and their natural enemies, using both ground survey data and UAV remote sensing data. The alfalfa was mowed twice to facilitate the transfer of this primary natural enemy to the cotton fields. Ground surveys were carried out every five days to gather data, while temporal niche and niche overlap methods were used for further analysis. Findings collected over a period ranging from day 31 to day 91 indicated that compared to their counterparts with no alfalfa traps, the cotton fields containing these pest control measures demonstrated a reduction in the A. gossypii population of approximately 16%. A survey conducted 5 days after mowing the alfalfa on days 61 and 71 found that the cotton fields with alfalfa traps experienced a 24.14% and 26.09% reduction in A. gossypii numbers. In contrast, the cotton fields without alfalfa traps experienced a 76.92% and 55.08% increase in cotton aphid numbers during the same period. It is noteworthy that the cotton fields with alfalfa traps showed a delayed onset of cotton aphid damage of approximately 5 days compared to the fields without alfalfa traps. This discovery has significant implications for understanding the ecological control mechanism of A. gossypii within alfalfa traps. Planting alfalfa traps around fields in Xinjiang could be promoted as a method to prevent and control aphid damage.

Second-growth forests of the Mexican tropics are reservoirs of timber species similar to old-growth forest: Perspectives for sustainable forest management

Second-growth forests represent the largest area of forest in southern Mexico and can provide relevant information on how their structural attributes in are linked to anthropogenic factors and for their forest management. However, a knowledge gap remains at national level with little scientific literature available. Therefore, this research aimed to investigate the structure and tree richness of second-growth forests in the south of Quintana Roo State, México. With stratified sampling through participatory mapping of local collaborators, secondary tropical forests of 7, 15, 27, 37, and ≥ 48 to 80 years (y) old-growth were identified. We categorized forests into three successional stage classes: 5-20 y (Class I; forests of 7 and 15 y); 25-40 y (Class II; forests of 27 and 37 y), and old-growth forest (Class III; forests 48-80 y). In each forest (7, 15, 27, 37, 48, and 80 y of time since abandonment [tSA]) three plots were randomly chosen and established within the forest. Each age class was composed of two forests and six sample plots. In total there were 18 plots of 500 m2 each. Subsequently, we: i) calculated the land use intensity (LUI) to which the sites were subjected, ii) described the following structural attributes: floristic similarity, true diversity (effective number of species), stem density, and basal area (AB), and iii) evaluated if tSA and LUI influence the aforementioned structural attributes. Tree diversity was characterized with Hill numbers associated with observed species richness (0D), richness of equally abundant species (1D), and dominant species (2D). Forest structure was analyzed by density (number of trees ha−1) and distribution of stems by diameter class ha−1 and basal area (BA, m2 ha−1). The second-growth forest was derived from the milpa agricultural system under moderate land use intensity (LUI index = 0.02 - 0.1). Floristic structure was at least similar between Class I and Class III. Forest age and LUI do not affect tree composition of the forests (p ≥ 0.1667). However, these two factors affected stem density and BA. Only the species richness (0D) of second-growth forest and old-growth forest was influenced by tSA (p = 0.0002). In second-growth forests, Classes I and II, 78 species (0D) were recorded, 8 and 8 exclusive species, 28 and 36 equally abundant species (1D), and 15 to 24 dominant species (2D). In the old-growth forest, Class III, 70 species were recorded, and 38 and 26 equally abundant (1D) and dominant species (2D), as well as 5 exclusive species. The density of stems decreased with increasing forest age and increasing BA. Second-growth forest and old-growth forest all showed a high density of small diameter stems. These results indicate that second-growth forests are important tree species reservoirs (including those for timber purposes), comparable to old-growth or mature forests, and therefore they are relevant not only as biodiversity conservation areas or carbon sinks, but also for planned sustainable forest management.

Pets, obesity and nurses: surgical site infections in the community.

Many surgical site infections (SSI) emerge after the patient is discharged from hospital. So, practice and district nurses should remain alert for SSIs and address modifiable risk factors, which include helping obese patients lose weight, optimising glucose control in people with diabetes and encouraging smoking cessation. Animals, including pets, are important reservoirs of resistant bacteria. By optimising SSI care, nurses can not only improve wound healing but also help preserve antibiotic efficacy.

Sedimentary facies analysis of a thin-bed-dominated turbidite succession in the Miocene Temburong Formation, Kampung Bebuloh, Labuan Island, Malaysia

Thin-bedded turbidites are important hydrocarbon-bearing reservoirs in many mature fields throughout the world. The type of turbidite depositional setting strongly influences vertical and horizontal continuity of the reservoir. However, distinguishing between lobe and levee associated thin-bedded turbidites remains challenging due to their generally similar facies characteristics. This study aims to contribute some insights to this problem by conducting a detailed bed-scale facies analysis on the Early Miocene Temburong Formation exposed at Kampung Bebuloh, Labuan Island, Malaysia, which may uncover features that can help in differentiating between both depositional types. Six facies are recognized in the Temburong Formation, which are interpreted as low density turbidites (F1–F4), hybrid event beds (F5), and sustained turbidites (F6). Detailed facies and ichnology analysis reveal features which are consistent with a lobe fringe deposit rather than levee-associated environment interpretation, including tabular bed geometries, presence of hybrid event beds, and the absence of thick-bedded channel-fill sandstones. Five facies associations are identified and interpreted as representing sub-environments within an overall lobe depositional setting. A diverse trace fossil assemblage, comprising the Nereites ichnofacies is consistent with a deep marine environment. Further identification of the Paleodictyon and Nereites sub-ichnofacies indicates a distal turbidite system setting, most likely lobe fringe. Based on the thick accumulation of FA2 and FA3 and no distinct observable vertical trend, the Early Miocene Temburong Formation in Labuan is interpreted as turbidites deposited at the fringes of lobe complexes rather than a single lobe fringe. Earlier works into the Temburong Formation in SW Labuan proposed a middle slope to proximal basin floor setting where the thin-bedded intervals were interpreted as potentially representing either levee deposits or the fringes of confined lobe deposits. Conversely, the Temburong Formation at Kampung Bebuloh exhibits characteristics of an unconfined lobe setting, suggesting an evolutionary change in depositional conditions over time.

Antibiofilm Activity of Combretum micranthum G. Don Catechin-Sugar Phytocomplex on Pseudomonas aeruginosa.

Clinicians often have to face infections caused by microorganisms that are difficult to eradicate due to their resistance and/or tolerance to antimicrobials. Among these pathogens, Pseudomonas aeruginosa causes chronic infections due to its ability to form biofilms on medical devices, skin wounds, ulcers and the lungs of patients with Cystic Fibrosis. In this scenario, the plant world represents an important reservoir of natural compounds with antimicrobial and/or antibiofilm properties. In this study, an extract from the leaves of Combretum micranthum G. Don, named Cm4-p, which was previously investigated for its antimicrobial activities, was assayed for its capacity to inhibit biofilm formation and/or to eradicate formed biofilms. The model strain P. aeruginosa PAO1 and its isogenic biofilm hyperproducer derivative B13 were treated with Cm4-p. Preliminary IR, UV-vis, NMR, and mass spectrometry analyses showed that the extract was mainly composed of catechins bearing different sugar moieties. The phytocomplex (3 g/L) inhibited the biofilm formation of both the PAO1 and B13 strains in a significant manner. In light of the obtained results, Cm4-p deserves deeper investigations of its potential in the antimicrobial field.

Abstract 1000: Platelets Act As Circulating Reservoir Of Tgfβ1: Role In Abdominal Aortic Aneurysms

Introduction: Transforming Growth Factor-Beta1 (TGFβ1) signaling plays a crucial role in the development and maintenance of the vasculature by orchestrating vascular remodeling signaling cascades. Aberrant TGFβ1 leads to aortic aneurysms, yet there is a persistent conflict in its role in driving or protecting against the degradation of the extracellular matrix (ECM) in abdominal aortic aneurysms (AAA). Notably, limited studies have delved into its cell-specific actions. This ambiguity highlights the need for an improved understanding of the TGFβ1 cell-specific role in AAA. Aims: To elucidate the role of platelet-derived TGFβ1 in AAA development thereon expanding our knowledge on the role of TGFβ1 in vascular remodeling. Methods and Results: Single-cell epitope and transcriptome analysis by using cellular-indexing of transcriptomes and epitopes by sequencing (CITE-seq) of the blood of patients with AAA revealed that platelets were enriched with TGFβ1 compared to healthy individuals. Comparative pathway analysis of the platelet populations showed the association of this cluster with ROS, platelet activation and chemokine signaling pathways that promote AAA pathogenesis. These results were validated in the Apolipoprotein E deficient (ApoE -/- ) mice treated with Angiotensin II for 28 days. To delve into the direct role of platelet-derived TGFβ1 in AAA, we generated mice with conditional knock-down of TGFβ1 in platelets (Tgfb1 flox/flox Pf4 Cre+ ) and subjected these mice to AAA. Remarkably, these mice exhibited reduced aneurysm development and preserved elastin microstructure compared to controls. The expression of phosphorylated smad2/3, one of the downstream TGFβ1-canonical signaling pathways, as well as matrix metalloproteinase, were repressed in the aorta of Tgfb1 flox/flox Pf4 Cre+ mice, suggesting the platelets could supplement Tgfb1 to the aortic tissue sufficient to fuel matrix degradation. These results were recapitulated when the platelets were depleted from the circulation using an anti-GP1b antibody. Conclusion: Our findings reveal that platelets represent an important reservoir of Tgfb1, clarify its cell-specific role in ECM remodeling and underscore its detrimental role in sustaining matrix degradation during AAA.

Prevalence of multidrug-resistant Campylobacter species in wastewater effluents: A menace of environmental and public health concern.

The prevalence of multidrug-resistant Campylobacter species in wastewater effluents presents a formidable challenge at the intersection of environmental sustainability and public health. This study examined the presence of multidrug-resistant Campylobacter in wastewater effluents in the Eastern Cape Province, South Africa, and its implications for environmental ecosystems and public health. Forty-five samples from household effluent (HHE) and wastewater treatment plant effluent (WWTPE) were collected at different geographical locations within the province between April and September 2022. The counts of the presumptive Campylobacter genus ranged from 5.2 × 103 to 6.03 × 104 CFU/mL for HHE and 4.93 × 103 to 1.04 × 104 CFU/mL for WWTPE. About 42.55% of the samples were positive for Campylobacter species. Five virulence determinants including the cadF and wlaN were detected in all the isolates; however, flgR (19.23%), ciaB, and ceuE (15.38%) were less prevalent. The antibiogram profiles of confirmed Campylobacter isolates revealed high resistance (>55%) against all tested antibiotics ranging from 55.77% (nalidixic acid) to 92.30% (erythromycin), and resistance against the other antibiotics followed the order ciprofloxacin (51.92%), azithromycin (50%), and levofloxacin (48.08%). On the contrary, gentamicin was sensitive against 61.54% of the isolates, followed by imipenem (57.69%) and streptomycin (51.92%). The WWTPE's antibiotic resistance index (ARI) was 0.19, lower than the permitted Krumperman threshold of 0.2; and HHE's ARIs were higher. The isolates' respective multiple antibiotic resistance indexes (MARI) varied between 0.08 and 1.00. Among the phenotypically resistant Campylobacter isolates examined, 21 resistance determinants encoding resistance against β-lactam, carbapenems, aminoglycosides, phenicol, quinolones, tetracyclines, and macrolides were detected, which explains the phenotypic resistance observed in the study. This study concludes that the wastewaters in the study areas are important reservoirs of multidrug-resistant and potentially pathogenic Campylobacter species, suggesting the need for proper treatment of the wastewaters to eliminate the organisms in the effluents before discharge the final effluent to the receiving watershed.

Efficacy of monthly treatment with oral fluralaner (Bravecto® 1-Month) against Tunga penetrans in dogs in Brazil: a randomized, double-blind, controlled field study.

Tungiasis is a neglected tropical disease caused by the adult female sand flea (Tunga penetrans). Dogs are considered important reservoirs of T.penetrans in Brazil. The aim of this study was to determine the monthly insecticidal efficacy of a single oral administration of fluralaner at a dose of 10-18mg/kg (Bravecto® 1-Month, also registered as Defenza® in some countries; MSD Animal Health) in dogs naturally infested with T. penetrans. This clinical trial was conducted in a rural community located in Ilhéus, Bahia, Brazil. A total of 64 dogs were selected and distributed in a completely randomized design between a treated group (TG) that received one single dose of Bravecto® 1-Month (Defenza®) and a negative control group (CG) that received no treatment. Each group was composed of 32 dogs. The evaluations took place on days 0, 7 ± 2, 14 ± 2, 21 ± 2, 28 ± 2, 35 ± 2, and 42 ± 2 post treatment, in which the dogs were inspected to evaluate the infestation stage and classify lesions associated with tungiasis. The primary efficacy was determined from the percentage of treated dogs free of fleas (stage II and III lesions) after administration of the formulation at each evaluation time. Secondary efficacy was based on the number of active lesions (stages II and III) in each group at each evaluation time. The clinical condition of the animals was defined based on the Severity Score for Acute Dog Tungiasis (SCADT), which is related to the number and severity of lesions. The primary efficacy of the product was greater than 95.0% from days 7 to 21 and reached 100.0% between days 28 and 42, with a significant association between treatment and infestation decline (P < 0.025) between days 7 and 42. Secondary drug efficacy was greater than 99.9% from days 7 to 21, reaching 100.0% between days 28 and 42 (P < 0.05). The treated dogs also scored lower on the SCADT than the control animals did during the entire clinical evaluation period (P < 0.05). A single administration of Bravecto® 1-Month (Defenza®) was effective in eliminating Tunga penetrans infestations, as well as in preventing parasitism for at least 42days after treatment.

Role of Maternal Antibodies in the Protection of Broiler Chicks against Campylobacter Colonization in the First Weeks of Life.

Thermophilic Campylobacter species are the most common cause of bacterium-mediated diarrheal disease in humans globally. Poultry is considered the most important reservoir of human campylobacteriosis, but so far, no effective countermeasures are in place to prevent the bacterium from colonizing broiler flocks. This study investigated maternal antibodies' potential to offer protection against Campylobacter in broiler chicks via a field trial and an immunization trial. In the field trial, breeder flocks with high and low anti-Campylobacter antibody levels in the yolk were selected based on serological screening. Offspring were subsequently monitored for maternal antibodies and Campylobacter prevalence during early life. Although maternal antibodies declined rapidly in the serum of broilers, offspring from flocks with lower anti-Campylobacter antibody levels seemed to be more susceptible to colonization. In the immunization trial, breeders from a seropositive breeder flock were vaccinated with an experimental bacterin or subunit vaccine. Immunization increased antibody levels in the yolk and consequently in the offspring. Elevated maternal antibody levels were significantly associated with reduced Campylobacter susceptibility in broilers at 2 weeks old but not at 1 and 3 weeks old. Overall, the protective effect of maternal immunity should be cautiously considered in the context of Campylobacter control in broilers. Immunization of breeders may enhance resistance but is not a comprehensive solution.

Spontaneous fermentation mitigates the frequency of genes encoding antimicrobial resistance spreading from the phyllosphere reservoir to the diet

The phyllosphere microbiome of vegetable products constitutes an important reservoir for multidrug resistant bacteria and Antibiotic Resistance Genes (ARG). Vegetable products including fermented products such as Paocai therefore may serve as a shuttle for extrinsic microorganisms with ARGs into the gut of consumers. Here we study the effect of fermentation on Paocai ARG dissemination by metagenomic analysis. Microbial abundance and diversity of the Paocai microbiome were diminished during fermentation, which correlated with the reduction of abundance in ARGs. Specifically, as fermentation progressed, Enterobacterales overtook Pseudomonadales as the predominant ARG carriers, and Lactobacillales and Enterobacteriales became the determinants of Paocai resistome variation. Moreover, the dual effect of microbes and metal resistance genes (MRGs) was the major contributor driving Paocai resistome dynamics. We recovered several metagenome-assembled genomes (MAGs) carrying acquired ARGs in the phyllosphere microbiome. ARGs of potential clinical and epidemiological relevance such as tet M and emrB-qacA, were mainly hosted by non-dominant bacterial genera. Overall, our study provides evidence that changes in microbial community composition by fermentation aid in constraining ARG dispersal from raw ingredients to the human microbiome but does not eliminate them.

Trichinella spiralis Infecting Wild Boars in West, Southwest, and Northwest of Romania: Evidence of an Underrated Risk.

The species of the genus Trichinella are etiological agents distributed all over the world and are able to infect mammals, birds, and reptiles. Trichinella spiralis is the species most adapted to domestic and wild pigs and is also the most important etiological agent of trichinellosis. The wild boar (Sus scrofa) is a nocturnal omnivorous mammal belonging to the Suidae family. S. scrofa has a great appetite and its diet includes a variety of small prey such as mice, rats, and other rodents, as well as carcasses of larger animals. The aim of this study was the identification and the molecular characterization of Trichinella larvae isolated from the muscle tissue of S. scrofa specimens collected in different counties of Romania. The muscle samples were examined by artificial digestion and the larvae identified at the species level by multiplex PCR. T. spiralis, a species that is able to infect a considerable number of different host species including humans, was identified. In Romania, S. scrofa is an important reservoir species for T. spiralis and plays an important role in linking the domestic and the wild cycle of Trichinella, with serious repercussions for human health.

Microfacies, diagenetic processes and reservoir quality of the Aptian carbonate Dariyan Formation, southeast of the Persian Gulf, South Iran

The Aptian carbonate Dariyan Formation (Shu'aiba equivalent) is one of the most important oil reservoirs in the Zagros Basin and the Persian Gulf (South and Southwest of Iran). The Dariyan Formation with mainly carbonate facies overlies the Gadvan (Hawar) Formation and is overlain by the Kazhdumi (Nahr Umr) Formation. Despite the reservoir importance of the Dariyan Formation, it seems that not much detailed work has been done about the facies characteristics, diagenetic processes and reservoir quality of this formation in the east of the Persian Gulf Basin of Iran.By using the new and valuable data obtained from the core, this study focused on the identification of microfacies, diagenetic processes, determining the sedimentary environment, biostratigraphy and reservoir characterization of this formation in one of the wells of Reshadat oilfield in the southeast of the Persian Gulf. The results obtained from microfacies study, led to the identification of seven carbonate and one mixed carbonate-clastic microfacies that were deposited in four facies belts including the inner ramp, middle ramp, outer ramp, and deep basin. Uniform facies changes and the absence of reef-forming organisms such as rudists and its replacement by Lithocodium algae with the ability to form patch reefs indicate the homoclinal carbonate ramp environment. The study of benthic and planktonic foraminifera, as well as algae, led to the identification of five biozones, which indicated the Aptian age for this formation.Based on petrographic study, the Dariyan Formation is affected by diagenetic processes such as Cementation, dissolution, mechanical and chemical compaction, dolomitization, bioturbation and pyritization. Correspondence of porosity and permeability data of the cores and petrophysical logs indicates that the reservoir quality of the Dariyan Formation in the studied field was affected by facies, and diagenesis factors. Reservoir characterization has revealed that the high quality zone is located in the intervals containing Lithocodium algae. In the Lithocodium-bearing facies (boundstone-floatstone) the presence of many interconnected pores and cavities in the skeletal network structure of Lithocodium/Bacinella algae have created a suitable reservoir quality and a permeable facies.

Molecular and histopathological survey of Francisella spp., Borrelia spp. and Leptospira spp. in ornamental birds of four provinces of Iran

Leptospirosis, tularemia, and Lyme disease are among the most important infectious diseases affecting humans, animals, and birds. The present study aimed to identify these infections in exotic birds in Iran using conventional PCR and histopathology methods. The samples consisted of 51 fecal samples and 70 tissue samples collected from 10 different species of ornamental birds in four cities in Iran (Tehran, Tabriz, Ahvaz, and Yazd), each with distinct geographical locations. The presence of bacterial diseases caused by Francisella, Borrelia, and Leptospira in birds was investigated using the 16SrRNA, 5S-23SrRNA, and 16SrRNA genes, respectively. Histopathological examination was conducted on the brain, lung, trachea, kidney, and liver. The results showed a positive rate of 9.91 % for Francisella spp. and 16.52 % for Leptospira spp. DNA in ornamental birds. However, Borrelia species were not identified based on the 5S-23SrRNA gene. Furthermore, the molecular prevalence based on the 16SrRNA gene was 9.9 % (12 out of 121 samples) for Francisella spp. and 16.5 % (20 out of 121 samples) for Leptospira spp. Histopathological studies revealed tracheitis, pneumonia, nephritis, and hepatitis in the PCR-positive birds. To the best of our knowledge, this report represents the first isolation of Leptospira spp. and Francisella spp. from birds in Iran. Considering that both identified bacteria are zoonotic agents, these findings demand a public health risk assessment of exotic birds, which could be important reservoirs for these infections.

Hospital Wastes as Potential Sources for Multi-Drug-Resistant ESBL-Producing Bacteria at a Tertiary Hospital in Ethiopia.

The hospital environment is increasingly becoming an important reservoir for multi-drug-resistant (MDR) Gram-negative bacteria, posing serious challenges to efforts to combat antimicrobial resistance (AMR). This study aimed to investigate the role of hospital waste as a potential source of MDR ESBL-producing bacteria. Samples were collected from multiple sources within a hospital and its vicinity, including surface swabs, houseflies, and sewage samples. The samples were subsequently processed in a microbiology laboratory to identify potential pathogenic bacteria and confirmed using MALDI-TOF MS. Bacteria were isolated from 87% of samples, with the predominant isolates being E. coli (30.5%), Klebsiella spp. (12.4%), Providencia spp. (12.4%), and Proteus spp. (11.9%). According to the double disc synergy test (DDST) analysis, nearly half (49.2%) of the bacteria were identified as ESBL producers. However, despite exhibiting complete resistance to beta-lactam antibiotics, 11.8% of them did not test positive for ESBL production. The characterization of E. coli revealed that 30.6% and 5.6% of them carried blaCTX-M group 1 type-15 and blaNDM genes, respectively. This finding emphasizes the importance of proper hospital sanitation and waste management practices to mitigate the spread of AMR within the healthcare setting and safeguard the health of both patients and the wider community.

Evaluation of particulate organic carbon from MODIS-Aqua in a marine-coastal water body.

La Paz Bay (LPB) in Mexico is one of the largest marine-coastal bodies of water in the Gulf of California (GC) and is ecologically important for the feeding, reproduction, and refuge of marine species. Although particulate organic carbon (POC) is an important reservoir of oceanic carbon and an indicator of productivity in the euphotic zone, studies in this region are scarce. This study evaluates the performance of satellite-derived POC in LPB from January 2003 to December 2020. The metrics obtained for COP ( ; y ), Chla-a ( ; y ), and SST ( ; y ) establish that although in some cases there was a slight over/underestimation, the satellite estimates consistently represent the variability and average values measured in situ. On the other hand, the spatio-temporal analysis of the POC allowed us to identify two seasons with their respective transition periods and five subregions in which the POC is characterized by having its maximum variability; two of these coincide with the locations of the eddies reported for the winter and summer seasons in the LPB, while the following three are located: one in the coastal zone and in the two areas in which the LPB interacts with the GC. The associations, variability nodes, and multiple linear regression analysis suggest that POC fluctuations in the LPB respond mainly to biological processes and, to some extent, to the seasonality of SST and wind. Finally, our results justify the use of the MODIS-Aqua satellite POC for studies in marine-coastal water bodies with similar characteristics to the LPB and suggest that this water body can be considered a reservoir for the marine region of northwestern Mexico.

Sulfate-reducing bacteria (SRB) mediated carbonate dissolution and arsenic release: Behavior and mechanisms

Carbonate bound arsenic act as an important reservoir for arsenic (As) in nature aquifers. Sulfate-reducing bacteria (SRB), one of the dominant bacterial species in reductive groundwater, profoundly affects the biogeochemical cycling of As. However, whether and how SRB act on the migration and transformation of carbonate bound arsenic remains to be elucidated. Batch culture experiment was employed using filed collected arsenic bearing calcite to investigate the release and species transformation of As by SRB. We found that arsenic in the carbonate samples mostly exist as inorganic As(V) (93.92 %) and As(III). The present of SRB significantly facilitated arsenic release from carbonates with a maximum of 22.3 μg/L. The main release mechanisms of As by SRB include 1) calcite dissolution and the liberate of arsenic in calcite lattices, and 2) the break of H-bonds frees arsenic absorbed on carbonate surface. A redistribution of arsenic during culture incubation took place which may due to the precipitation of As2Sx or secondary FeAl minerals. To our best knowledge, it is the first experimental study focusing on the release of carbonate bound arsenic by SRB. This study provides new insights into the fate and transport of arsenic mediated by microorganism within high arsenic groundwater-sediment system.

Sponge Communities of Submarine Caves and Tunnels on the Fernando de Noronha Archipelago, Northeast Brazil

Submarine caves are important biodiversity reservoirs, but there is little information about the biota of marine caves in the Southwestern Atlantic. Here, we describe three submarine cavities and their sponge communities on the Fernando de Noronha Archipelago, Northeast Brazil. The underwater cavities were explored and collections were made through scuba diving from 5 to 18 m depths. Sapata Cave has a wide semi-dark zone near the entrance, a narrow transition zone, and a dark chimney, which is closed at the top. Ilha do Meio Cave is narrower and shallower than Sapata Cave, but has a long passage that leads to two completely dark rooms. Pedras Secas Tunnel has only a semi-dark zone with high water movement. The sponge communities in the semi-dark zones of the three cavities are rich and dominated by the classes Demospongiae and Homoscleromorpha, but Calcarea are also common. The transition zones of both caves are dominated by a desma-bearing sponge, thinly encrusting spirastrellids, and small Homoscleromopha and Calcarea. The dark zone in Ilha do Meio Cave is almost azoic, with only three species. This study has increased the number of sponge species known in submarine cavities on Fernando de Noronha from 29 to 69, highlighting the great richness of the sponge communities in these cryptic environments.

Genetic drift and purifying selection shape within-host influenza A virus populations during natural swine infections.

Patterns of within-host influenza A virus (IAV) diversity and evolution have been described in natural human infections, but these patterns remain poorly characterized in non-human hosts. Elucidating these dynamics is important to better understand IAV biology and the evolutionary processes that govern spillover into humans. Here, we sampled an IAV outbreak in pigs during a week-long county fair to characterize viral diversity and evolution in this important reservoir host. Nasal wipes were collected on a daily basis from all pigs present at the fair, yielding up to 421 samples per day. Subtyping of PCR-positive samples revealed the co-circulation of H1N1 and H3N2 subtype swine IAVs. PCR-positive samples with robust Ct values were deep-sequenced, yielding 506 sequenced samples from a total of 253 pigs. Based on higher-depth re-sequenced data from a subset of these initially sequenced samples (260 samples from 168 pigs), we characterized patterns of within-host IAV genetic diversity and evolution. We find that IAV genetic diversity in single-subtype infected pigs is low, with the majority of intrahost Single Nucleotide Variants (iSNVs) present at frequencies of <10%. The ratio of the number of nonsynonymous to the number of synonymous iSNVs is significantly lower than under the neutral expectation, indicating that purifying selection shapes patterns of within-host viral diversity in swine. The dynamic turnover of iSNVs and their pronounced frequency changes further indicate that genetic drift also plays an important role in shaping IAV populations within pigs. Taken together, our results highlight similarities in patterns of IAV genetic diversity and evolution between humans and swine, including the role of stochastic processes in shaping within-host IAV dynamics.